I ran into a well-known, but odd IE6 caching bug this week. If caching is turned off for IE6 browsers, modifying DOM elements triggers the browser to reload any resources referenced by the changed elements. So if a script changes the class name of 5 elements and the CSS classes have a background image property, then the background image will be reloaded once for each DOM update. This sucks the performance out of a web application.

There are several work arounds, but the best I’ve found is a simple IE6 Javascipt toggle that turns off the behaviour.

Skripteka is a large library of Prototype extensions and scripts.

The prototype.js library adds some more depth, adding a cleaner, richer way to work with objects in Javascript. The more I use Javascript, the more I like it.

I embedded the Mozilla JavaScript interpreter some years ago, and I remember fighting with porting the implementation (fixing several bugs on Alpha/Tru63). I also remember the pain caused by the lack of standard libraries, and the void of debugging tools. Things have changed. Today there are libraries like Prototype.js and tools like Firebug.

A case against using the prototype.js library.

AJAX Edit In Place With Prototype, Version 0.2.0.

Developer Notes for prototype.js, a fairly complete set of examples of this handy library.

An example of edit-in-place with prototype.js. Prototype is the excellent JavaScript library for hooking events and doing asynchronous HTTP.

A Quick Guide to Prototype, the handy-dandy Javascript library for DOM access and asyncronous HTTP requests.

These are my picks for the best base Javascript libraries:

• moo.ajax, a miniscule wrapper for asynchronous XMLHttp requests
• moo.fx, a itty-bitty browser fx lib
• The Yahoo UI library, a larger, but very complete set of tools
• The prototype.js framework (it’s really an Ajax class library) and its wiki
• The rico javascript effects library
• The sajax simple Ajax library
• The Behaviour DOM access library
• And lastly, the defacto script.aculo.us libraries
• And if the above is geek to you, try this ‘Ajax’ overview at the Ajaxian blog, or the Wikipedia article on Ajax (programming)